RU1793214C - Photoelectric displacement transducer - Google Patents

Abstract

The invention relates to the field of technical measurements, and in particular to photographic systems. The aim of the invention is to simplify and improve the accuracy of alignment of the phase position of the raster sections. The photoelectric displacement transducer contains a measuring raster ruler, an indicator ruler with four sections of the raster shifted relative to each other by 1/4 of the period, a illuminator and photo arrays under each section of the indicator raster. Photodetectors are connected in pairs through one, mounted on a common carriage mounted with the possibility of sliding along indicator line. The distances between the end of the first and the beginning of the third raster and between the end of the first and the beginning of the third photodetector are equal. The distances between the beginning of the second and the beginning of the fourth raster and between the beginning of the second and the beginning of the fourth photodetectors are equal. The length of the solution sections exceeds the length of the photodetectors. When adjusting, the carriage with photodetectors is shifted to the right or left, depending on the angle of shift, so that either the first or third photodetector is partially below the adjacent second portion of the solution, which equalizes the phase shift strictly by 90 el. Degrees, 3 ill. . w Ј

Description

The invention relates to the field of technical measurements, and in particular to raster systems.

A photoelectric displacement transducer is known, comprising a measuring raster ruler, an indicator ruler with four sections of the raster shifted relative to each other by 1/4 of the period, a illuminator, photodetectors under each section of the indicator raster, connected in pairs through one.

It is technically difficult to precisely set the phase position of the raster sections in this device.

The aim of the proposal is to simplify and improve the accuracy of alignment of the phase position of the raster sections.

This goal is achieved by the fact that in the photoelectric transducer containing the measuring raster line, the indicator line with four sections of the raster, shifted relative to each other by 1/4 period, a illuminator, photodetectors located under each section of the indicator raster and connected in pairs through one, photodetectors mounted on a common carriage mounted with the possibility of shifting along the indicator line, while

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the distances between the end of the first and the beginning of the third raster, between the end of the first and the beginning of the third photodetectors are equal, the distances between the beginning of the second and the beginning of the fourth photodetector, between the beginning of the second and the beginning of the fourth photodetectors are equal and the length of the sections of the solution exceeds the length of the photodetectors connected with them.

Figure 1 shows the arrangement of rasters and photodetectors; figure 2,3 is a phase diagram.

The device comprises a illuminator 1, a capacitor 2, a measuring line 3 with a raster, an indicator line 4 with four sections of rasters 5,6,7,8, photodetectors 9,10,11,12 in each section of the raster, photodetectors are mounted on a common carriage 13 installed with the possibility of shifting relative to the indicator raster. The sections of the rasters of the indicator line 4 are shifted relative to each other by 1/4 of the period. The outputs of the photodetectors 9 and 11, 10 and 12, respectively, are connected in opposite pairs. The length of the raster sections exceeds the length of the photodetectors. The distances between the end of the raster 5 and the beginning of the raster 7, between the end of the photodetector 9 and the beginning of the photodetector 11 are equal, the distance between the beginning of the raster 6 and the beginning of the raster 8, between the beginning of the photodetector 10 and the beginning of the photodetector .12 are equal. The signal from the photodetectors 9 and 11 is conventionally accepted as varying in cosine; then the signal from the photodetectors 10 and 12 will change in sine.

The converter operates as follows.

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When the measuring line 3 is moved relative to the indicator line 4, the rasters 5,6,7,8 modulate the radiation flux of the illuminator 1. As a result, electrical signals are generated at the output of the photodetectors 9, 11 and 10, 12 with a frequency proportional to the speed of movement and amplitude A proportional to the light flux incident on the photosensitive area of the photodetectors, wherein the signal from the photodetectors 10, 12 is determined by the expression o) t, and the signal from the photodetectors 9.11 by the expression (A + Ai) coso t.

In the presence of a phase shift, which determines its deviation from 90 el. grad., the carriage 13 is shifted. If p O, the phase shift between the output signals is adjusted by moving the carriage 13 to the right, while the signals from the photodetectors 10, 11, 12 remain the same, and since the photodetector 9 is partially under raster 6 ,. its initial signal will change by a value of 5 ctasin a t, which will help to equalize the phase shift strictly by 50 electric degrees, as can be seen from the diagram of Fig. 2.

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If p 0 /, the phase shift between the output signals is adjusted by moving the carriage 13 to the left. In this case, the signal from the photodetector .11 changes by the value of ct2Sln, a phase shift occurs, which is explained by the diagram

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After adjustment, the device is operated in the usual way.

Claims (1)

SUMMARY OF THE INVENTION A photovoltaic displacement transducer comprising a measuring raster array, an indicator ruler with four raster sections phase-shifted relative to each other by 1/4 period, an illuminator, photodetectors installed under each section of the indicator raster and connected in pairs through one, characterized in that that, in order to simplify and improve the accuracy of adjusting the phase position of the raster sections, the photodetectors are mounted on a common carriage mounted with the possibility of shifting along the indicator the distance between the end of the first and the beginning of the third photodetector, equal to the distance between the end of the first and the beginning of the third photodetector, and the distance between the beginning of the second and the beginning of the fourth photodetector, while the length of the raster sections exceeds the length of the photodetectors associated with them. . L to 07 // /  Zasinttft Si / 2 / l5i / ajt